User access system for district heating and cooling system

Abstract

The invention discloses a user access system for a district heating and cooling system. The system comprises a static flow balancing valve, a self-operated pressure difference control valve, a proportional-integral electric valve, a temperature transmitter and a PID controller. The PID controller is connected with the proportional-integral electric valve and the temperature transmitter. The proportional-integral electric valve is installed on a water return pipe of each user branch cooling and heating primary side pipe net, the temperature transmitter is installed on a water return pipe of each user cold water and hot water secondary side pipe net, the temperature transmitter transmits detected temperature information to the PID controller, and the PID controller controls the valve openingof the proportional-integral electric valve based on the information. Pipe net conveyed cold-hot water home-entry flow and pressure are adjusted to be within the working range of the proportional-integral electric valve, and automatic control is convenient.

Description

technical field [0001] The invention relates to the field of district energy cooling and heating, in particular to a user access system for district cooling and heating systems. Background technique [0002] The district cooling and heating system is to meet the air-conditioning cold source / heat source requirements of multiple buildings in a specific area. The cold water / hot water is prepared centrally by a special energy station, and the chilled water / hot water is supplied through the regional pipe network. Cooling and heating system. The low-temperature chilled water or hot water prepared by the energy station is transported to the user panel exchange room through the regional pipe network, and then transported back to the energy station after heat exchange. The district cooling and heating system adopts a closed cycle and is completely separated from the user access system. The main considerations are to reduce the pressure on the system, facilitate adjustment, and meet...

AI Technical Summary

Problems solved by technology

[0005] (1) The temperature of the secondary water supply is difficult to control, the control method is single, and the most energy-saving operation mode cannot be used according to different situations, different needs, and different time periods;

[0006] (2) The energy consumption of the regulating valve is serious, and the output flow of the circulating pump and the water supply pump cannot change with the change of the cooling and heating load and the pressure of the pipe network, but always maintains a constant flow

When the flow needs to be adjusted, it is usually adjusted manually by opening a large valve or closing a small valve. The adjustment cycle is long, resulting in a great waste of electric energy and difficult to adjust.

Moreover, additional losses are generated on the valve, which also wastes a lot of energy

[0007] (3) The authority of the user's regulating valve deviates from the working range, and cannot play its due regulating role

[0008] The use of frequency conversion speed regulation system to control the circulating pump can avoid the energy loss caused by valve adjustment, but how to reasonably collect the data of each control node in the heating system and use the above data as parameters to control the frequency conversion system to realize centralized supply The intelligent control of the thermal system has become an urgent problem to be solved in the prior art

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